User-friendly and versatile software for analysis of protein hydrophobicity.

We have developed a simple and flexible program to analyze regional hydrophobicity of a protein from its amino acid (aa) sequence. This program runs as a Microsoft Excel document into which aa sequence can be copied from any Windows-compatible or Macintosh word processor. The program returns the hydrophobicity index of each aa residue and other analyses that can be used to predict transmembrane domains, amphiphilic alpha helices and putative antigenic epitopes in a protein using established algorithms. The program can also be easily modified to test user-defined algorithms and to accommodate non-conventional aa residues or ambiguities in the aa sequence. Simple modification of the program allows direct use of nucleic acid sequence information for various analyses. Graphic visualization of the results is readily achieved using the graphics function of Microsoft Excel. Alternatively, the data can be imported into other graphics software for preparation of publication-quality figures. By running as a document in Microsoft Excel, which can be found in virtually all personal computers, this program provides easy access even to the computer novice.